Why arent my goose eggs fertile?

[Insane poultry mama]

Hey yall! I have a male and a female african geese that are one year old. The female has been laying eggs and everyday i take them out to the baby pool and they breed. She's up to about ten eggs now and I've been saving them for her to incubate when she's done in a cooler with appropriate temperature and humidity. I started incubating some of the older ones cause she's taking a while to go broody and i wanted to get the most out of her production. When i cracked the really older ones they werent fertilized cause they didnt have the ring. Would older eggs not have the ring even if they did when they were fresh? It's been eight days since I started incubating the older eggs and im not seeing any veins. What's going on here? My gander has been breeding my goose every day and it looks like he's being successful. Any tips or ideas?

 

[AshVau22]

How old are the eggs before you started trying to incubate them?

 

[Insane poultry mama]

5 to 7 days old.

 

[Insane poultry mama]

Is there a way to tell if a goose is infertile?

 

[AshVau22]

Is there a way to tell if a goose is infertile?

I don't have the knowledge in that area hopefully some goose experts can answer that. Sorry I can't be more helpful.

 

[Kiki]

Are you 100% sure of what the actual temperature is in your incubator?
Do you have multiple tested thermometers in it?